Fragment containing the oxygen-dependent degradation (ODD) domain of the Drosophila melanogaster sima gene. Under normoxia, the P850 residue in the ODD domain is hydroxylated by the Hph prolyl hydroxylase (FBrf0189809), which results in the Vhl ubiquitin ligase targeting the sima protein for ubiquitination and proteasomal degradation (FBrf0129709). Under hypoxia, the protein is stabilized (FBrf0152214). If fused to an appropriate reporter protein, Tag:ODD(sima) can thus be used to generate a genetically encoded biosensor for visualizing hypoxia in vivo (FBrf0234807).